Practice Quiz

Microbes, Food Spoilage, and Food Preservation

Directions

• Click anywhere on the screen or hit the down arrow to move to the next slide.

• Write each answer on a piece of paper to test yourself. Count the number correct.

• Study the ideas and words that you get wrong. Good Luck!

Question 1:

Which microbes are most likely to spoil food and make us sick?

Answer:

Bacteria

Question 2:

What are the two types of bacteria?

Answer:

Archaebacteria and Eubacteria

Question 3:

What conditions are best for bacterial reproduction?

Answer:

A. Nutrients

B. Moist Environment (Water)

C. Proper temperature (danger zone)

D. Proper pH

Question 4:

What is the temperature “danger zone” that is best for bacterial reproduction?

Answer:

40° to 140° F

Question 5:

What is the pH “danger zone” that is best for bacterial reproduction?

Answer:

pH 4.6 to 10, but pH closest to 7 is best for bacteria

Question 6:

What are the “4 C’s” to prevent foodborne illness?

Answer:

• Cook

• Chill

• Clean

• Combat Cross Contamination

Question 7:

What is the range of pH on the pH scale?

Answer:

The pH scale ranges from 0 to 14

Question 8:

What pH is an acid?

Answer:Any substance with a pH below 7 is an acid.

Question 9:

What is a base?

Answer:

Any substance with a pH above 7 is a base.

Question 10:

What are the two main goals of food preservation?

Answer:

A. Prevent food spoilage

B. Prevent the growth of pathogens in food

Question 11:

What is a pathogen?

Answer:

A pathogen is a microbe that can cause disease.

Question 12:

What are the three main shapes of bacteria?

Answer:

• Bacilli = rod-shaped

• Cocci = sphere-shaped

• Spirilla = spiral-shaped

Question 13:

Where are bacteria normally found in the human body?

Answer:

Harmless and helpful bacteria are found in our mouths, sinuses, throats, and intestines.

Question 14:

About what percentage of bacteria are pathogens?

Answer:

Approximately 1% of bacteria are pathogens.

Question 15:

How fast can bacteria reproduce in perfect conditions?

Answer:

Some bacteria can reproduce every 20 minutes in perfect conditions.

Question 16:

What is a flagellum?

Answer:

A flagellum is a whip-like structure on the outside of a bacterium. The flagellum helps the bacterium

move.

Question 17:

List at least two examples of ways in which bacteria help us.

Answer:

1. Bacteria turn milk into yogurt and cheese.

2. Bacteria help digest food in our intestines.

3. Some bacteria are decomposers.  That is, they feed on decaying matter and break it down.

Question 18:

What is Binary fission?

Answer:Binary fission is the process by which a bacterium divides into two cells.  Each cell

is an exact copy of the original cell.

Question 19:Why is a bacterium considered to be a

prokaryote?

Answer:

A bacterium is considered to be a prokaryote because it does not have a

nucleus.

Question 20:

Which method of food preservation lowers temperatures between 32° F and 40 ° F ?

Answer:

Refrigeration

Question 21:

Which method of food preservation lowers temperatures below 32° F?

Answer:

Freezing

Question 22:

Which method of food preservation uses acid to change the food and prevent

bacterial reproduction ?

Answer:

Fermentation° F° F

Question 23:

Which method of food preservation involves high energy which kills microbes ?

Answer:

Irradiation° F° F

Question 24:

Which method of food preservation removes water from food to prevent bacterial growth?

Answer:

Dehydration (or drying)° F° F

Question 25:

Which method of food preservation heats food (usually liquid) to a high heat for a

short time to kill most microbes?

Answer:

Pasteurization° F° F

How many did you get correct?

23-25 - Awesome! You’re ready - continue your review.

20-22 - Pretty good. You’re ready, but should review a bit more.

17-19 - Hmm. You need to study more.

< 17 - You really need to study your definitions and practice problems.